code: def test_reference_wrapper():
      """#171: Can't return reference wrappers (or STL data structures containing them)"""
      from pybind11_tests.issues import (
          Placeholder,
          return_vec_of_reference_wrapper,
      )
  
      assert (
          str(return_vec_of_reference_wrapper(Placeholder(4)))
          == "[Placeholder[1], Placeholder[2], Placeholder[3], Placeholder[4]]"
      )
  
file_path: turicreate/src/external/coremltools_wrap/coremltools/deps/pybind11/tests/test_issues.py
imports: import pytest
  from pybind11_tests import ConstructorStats
label_desc: Use image node_id 3 for calling a global function with example usage: test_reference_wrapper() without return types